FIELD OF THE INVENTION
[0001] The present invention relates to the securing, or locking, of aircraft doors or access
panels into openings formed in an aircraft fuselage.
BACKGROUND
[0002] Avionics bay doors, or hinged access panels, of aircraft are secured so that they
do not open during flight.
[0003] Conventionally, the securing of a hinged access panel on an aircraft is performed
using a plurality of panel fasteners to attach the panel to the aircraft fuselage
such that it does not move relative to the fuselage. Typically, depending on the size
of the aircraft door or panel, twenty to thirty such fasteners may be used.
[0004] The fastener heads of the panel fasteners may be visible to radar systems. Also,
fastener heads tends to have a limited life.
[0005] The securing of a hinged access panel on an aircraft using a plurality of panel fasteners
tends to be a time consuming and costly process.
SUMMARY OF THE INVENTION
[0006] In a first aspect, the present invention provides locking apparatus for an aircraft
door or access panel, the locking apparatus being for securing the aircraft door or
panel in an opening formed in an aircraft fuselage. The locking apparatus comprises
a shaft having a longitudinal axis, at least one mounting member for mounting the
shaft to the aircraft fuselage such that the shaft may be rotated about its longitudinal
axis, door/panel securing means fixedly mounted to the shaft and arranged such that:
rotation of the shaft about its longitudinal axis moves the securing means from being
in a first position to being in a second position (the first position being such that
the securing means are not coupled to the aircraft door/panel such that movement of
the aircraft door/panel relative to the aircraft fuselage is permitted, and the second
position of the securing means being such that the securing means are engaged with
the aircraft door/panel such that movement of the aircraft door/panel relative to
the aircraft fuselage is opposed or prevented), a locking member for coupling to the
shaft such that rotation of the shaft about its longitudinal axis causes movement
of the locking member, and fixing means for, when the shaft has been rotated such
that the securing means are in the second position, fixedly attaching the locking
member to the aircraft fuselage thereby preventing rotation of the shaft.
[0007] The locking member may be configured to be coupled to the shaft such that the locking
member forms a lever that is rotatable about a fulcrum, the fulcrum being the longitudinal
axis of the shaft.
[0008] The locking member may be configured to be fixedly attached, by the fixing means,
to the aircraft fuselage at a point along a length of the locking member that is proximate
to a distal end of the locking member (i.e. an end of the locking member that is furthest
away from the fulcrum).
[0009] The locking member may be configured to be fixedly attached, by the fixing means,
to the aircraft fuselage, at a plurality of different points on the locking member.
[0010] The shaft may comprise a bolt, a longitudinal axis of the bolt being aligned with
the longitudinal axis of the shaft.
[0011] The locking member may comprise a hole, the shape of the hole corresponding to the
shape of the bolt such that the locking member may be coupled to the shaft by positioning
the locking member relative to the shaft such that the bolt is in the hole.
[0012] The shaft may comprise a notch, a diameter of the notch being less than a diameter
of the hole in the locking member such that, when the locking member is positioned
relative to the shaft such that the notch is in the hole, the locking member may be
rotated about the longitudinal axis of the shaft without the shaft being rotated,
thereby allowing an orientation of the locking member relative to the shaft to the
adjusted.
[0013] The shaft may comprise an adjustment bolt, a longitudinal axis of the adjustment
bolt being aligned with the longitudinal axis of the shaft, the adjustment bolt being
positioned at point along the length of the shaft such that, using the adjustment
bolt, a human operator may rotate the shaft.
[0014] The fixing means may comprise a clamping block that is fixedly attached to the aircraft
fuselage and may be configured to provide one or more surfaces that are substantially
perpendicular to the longitudinal axis of the shaft.
[0015] The locking member may be fixedly attached to the aircraft fuselage by fixedly attaching
the locking member to a surface of the clamping block that is substantially perpendicular
to the longitudinal axis of the shaft.
[0016] The locking member may be configured to be fixedly attached the clamping block by,
for one of more bolts, positioning each of those bolts such that that bolt is within
a respective hole through the locking member and in a respective hole in the clamping
block.
[0017] The locking mechanism may further comprise one or more clamping brackets (e.g. handle-like
brackets) fixedly attached to the aircraft door/panel, wherein the securing means
are configured to attach to each of the one or more clamping brackets.
[0018] The securing means may include one or more locking brackets (e.g. hook-like, or hook-shaped,
brackets), each locking bracket being fixedly attached to the shaft at a position
along the length of the shaft, each locking bracket being configured to be hooked
onto a respective clamping bracket such that that clamping bracket is securely held
by that locking bracket.
[0019] The aircraft door or access panel may be a hinged door or access panel.
[0020] The shaft, the at least one mounting member, the securing means, the locking member,
and/or the fixing means may be made of metal (e.g. steel).
[0021] In a further aspect, the present invention provides an aircraft comprising an aircraft
door or access panel, an aircraft fuselage, and locking apparatus for securing the
aircraft door/panel in an opening formed in the aircraft fuselage, the locking apparatus
being in accordance with the first aspect of the present invention.
[0022] In a further aspect, the present invention provides a method of securing an aircraft
door or access panel in an opening formed in an aircraft fuselage, the method comprising:
providing a shaft having a longitudinal axis, the shaft being mounted, by at least
one mounting member, to the aircraft fuselage such that the shaft may be rotated about
its longitudinal axis; providing door/panel securing means, the securing means being
fixedly mounted to the shaft; rotating the shaft, thereby moving the securing means
from being in a first position to being in a second position, the first position being
such that the securing means are not coupled to the aircraft door/panel such that
movement of the aircraft door/panel relative to the aircraft fuselage is permitted,
and the second position of the securing means being such that the securing means are
engaged with the aircraft door/panel such that movement of the aircraft door/panel
relative to the aircraft fuselage is opposed or prevented; coupling a locking member
to the shaft such that rotation of the shaft about its longitudinal axis causes movement
of the locking member; and, when the shaft has been rotated such that the securing
means are in the second position, fixedly attaching, using fixing means, to the aircraft
fuselage, the locking member, thereby preventing the shaft from rotating.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023]
Figure 1 is a schematic illustration (not to scale) showing a perspective view of
components of a fastening system;
Figure 2 is a schematic illustration (not to scale) showing certain components of
the fastening system in greater detail;
Figure 3 is a schematic illustration (not to scale) showing certain components of
the fastening system in greater detail;
Figure 4 is a schematic illustration (not to scale) showing a perspective view of
components of the fastening system;
Figure 5 is a schematic illustration (not to scale) of a perspective view of a locking
plate;
Figure 6 is a process flow chart showing certain steps of an embodiment of a process
of using the fastening system;
Figure 7 is a schematic illustration (not to scale) showing an example configuration
of components of the fastening system at a certain step of the process of Figure 6;
and
Figure 8 is a schematic illustration (not to scale) showing an example configuration
of components of the fastening system at a certain step of the process of Figure 6.
DETAILED DESCRIPTION
[0024] Figure 1 is a schematic illustration (not to scale) showing a perspective view of
an embodiment of a fastening system 1 for fastening, or fixing, an aircraft door or
hinged access panel of an aircraft (hereinafter referred to as the "aircraft door"
and indicated in Figure 1 by the reference numeral 2) against the aircraft fuselage
4.
[0025] In this embodiment, when not fixed by the fastening system 1, the aircraft door 2
is movable with respect to aircraft fuselage 4. For example, the aircraft door 2 may
be mounted to the aircraft fuselage 4 via (e.g. two or more) hinges (not shown in
the Figures). The aircraft door 2 and the aircraft fuselage 4 are parts of an aircraft.
[0026] In this embodiment, the fastening system 1 comprises a shaft 8, two shaft mounts
10, three hook-shaped, or hook-like, locking brackets 12, and three clamping brackets
14. Also, the system further comprises a clamping block (not shown in Figure 1) and
a locking plate (not shown in Figure 1). The clamping block is described in more detail
later below with reference to Figure 4. The locking plate is described in more detail
later below with reference to Figure 5.
[0027] The fastening system 1 (including the later described clamping block and locking
plate) may be entirely located within the aircraft whose aircraft door 2 is to be
fastened by the fastening system 1.
[0028] In this embodiment, the shaft 8 is rotatable about its longitudinal axis, as indicated
in Figure 1 by solid arrows. The shaft 8 is a tubular shaft that is made of metal.
[0029] In this embodiment, the shaft 8 is securely mounted to the aircraft fuselage 4 via
the two shaft mounts 10 and end brackets (not shown in Figures for reasons of clarity).
In other embodiments, the shaft 8 may be mounted to the aircraft fuselage 4 using
a different number of shaft mounts 10. The mounting of the shaft 8 to the aircraft
fuselage 4 is such that the shaft 8 may be rotated about its longitudinal axis, and
such that movement of the shaft 8 in a direction that is perpendicular to the longitudinal
axis of the shaft is substantially prevented.
[0030] In this embodiment, the shaft mounts 10 are made of metal. The shaft mounts 10 are
securely mounted to the aircraft fuselage 4 such that the positions of the shaft mounts
10 with respect to the aircraft fuselage 4 are fixed. The shaft mounts 10 are described
in more detail later below with reference to Figure 2.
[0031] In this embodiment, the shaft 8 passes through a hole 16 in the aircraft fuselage
4 such that a first end 18 of the shaft 8 (indicated in Figure 1 by dotted lines)
is located at a different side of the aircraft fuselage 4 to the side of the aircraft
fuselage 4 at which a second end 20 of the shaft 8 is located. The first end 18 of
the shaft 8 and the second end 20 of the shaft 8 are opposite ends of the shaft 8.
[0032] The first end 18 of the shaft 8 is described in more detail later below with reference
to Figure 4.
[0033] In this embodiment, the locking brackets 12 are made of metal. The locking brackets
12 are fixed to the shaft 8 (e.g. by welding or by being bolted) such that the position
of a locking bracket 12 relative to the shaft 8 is fixed. Each locking bracket 12
is fixed to the shaft 8 at a position along the length of the shaft 8 that is opposite
to a respective clamping bracket 14. Also, as described in more detail later below
with reference to Figures 2 and 3, each locking bracket 12 is configured to be hooked
(by rotating the shaft 8 about its longitudinal axis) onto a respective clamping bracket
14 such that that clamping bracket 14 is securely held by that locking bracket 12.
In this embodiment, when one of the locking brackets 12 is hooked onto its respective
clamping bracket 14, each of the other locking brackets 12 hooks onto their respective
clamping brackets 14. Similarly, in this embodiment, when one of the locking brackets
12 is not hooked onto its respective clamping bracket 14, each of the other locking
brackets 12 is not hooked onto their respective clamping brackets 14.
[0034] In this embodiment, the clamping brackets 14 are made of metal. The clamping brackets
14 are securely mounted to the aircraft door 2 such that the positions of the clamping
brackets 14 with respect to the aircraft door 2 are fixed. Each clamping bracket 14
is fixed to the aircraft door 2 such that it is opposite to a locking bracket 12 on
the shaft 8. As described in more detail later below with reference to Figures 2 and
3, each clamping bracket 14 comprises a crossbar shaft and roller around which a respective
locking bracket 12 may be securely hooked. Thus, in effect, each of the clamping brackets
14 is a handle that may be held by, i.e. securely hooked onto by, a respective hook-shaped
locking bracket 12.
[0035] In this embodiment, there are three locking brackets 12 and three corresponding clamping
brackets 14. However, in other embodiments, there may be a different number of locking
bracket-clamping bracket pairs.
[0036] Figure 2 is a schematic illustration (not to scale) showing further detail of the
shaft 8, a shaft mount 10, a locking bracket 12, and clamping brackets 14 corresponding
to that locking bracket 12.
[0037] In this embodiment, each shaft mount 10 is fixed to the aircraft fuselage 4 by a
first set of bolts, each of which is hereinafter referred to as a "first bolt" and
is indicated in the Figures by the reference numeral 22. Each of the first bolts 22
passes through the body of a shaft mount 10 and into the aircraft fuselage 4, thereby
securely fixing that shaft mount 10 to the aircraft fuselage 4. In this embodiment,
each shaft mount 10 is fixed to the aircraft fuselage 4 by four first bolts 22. However,
in other embodiments, each shaft mount 10 may be fixed to the aircraft fuselage 4
by a different number of bolts, or using different fixing means.
[0038] In this embodiment, each shaft mount comprises a clamp 24 that clamps around the
shaft 8. The clamp 24 of each shaft mount 8 is configured to allow the shaft 8 to
be rotated about its longitudinal axis. Also, the clamp 24 of each shaft mount 10
is configured to prevent or oppose movement of the shaft 8 in a direction that is
perpendicular to the longitudinal axis of the shaft 8. Each of the clamps 24 is secured
around the shaft 8 by a second set of bolts, each of which is hereinafter referred
to as a "second bolt" and is indicated in the Figures by the reference numeral 26.
Each of the second bolts 26 passes through the two clamping jaws that form each clamp
24, thereby securely fixing that clamp 24 around the shaft 8. In this embodiment,
each clamp 24 is fixed around the shaft 8 by two second bolts 26. However, in other
embodiments, each clamp 24 may be fixed around the shaft 8 by a different number of
bolts, or using different fixing means. Also, in other embodiments, the shaft 8 may
be fixed to the aircraft fuselage 4 (such that rotation of the shaft about its longitudinal
axis is permitted) by a different holding means.
[0039] In this embodiment, each clamping bracket 14 is fixed to the aircraft door 2 by a
third set of bolts, each of which is hereinafter referred to as a "third bolt" and
is indicated in the Figures by the reference numeral 28. Each of the third bolts 28
passes through the body of a clamping bracket 14 and into the aircraft door 2, thereby
securely fixing that clamping bracket 14 to the aircraft door 2. In this embodiment,
each clamping bracket 14 is fixed to the aircraft door 2 by four third bolts 28. However,
in other embodiments, each clamping bracket 14 may be fixed to the aircraft door 2
by a different number of bolts, or using different fixing means.
[0040] In this embodiment, each clamping bracket comprises a crossbar shaft and roller (which
is hereinafter referred to as the "crossbar" and indicated in the Figures by the reference
numeral 30) onto which a respective locking bracket 12 may be securely hooked.
[0041] In Figure 2, the locking bracket 12 is not hooked onto the respective crossbar 30.
Thus, in Figure 2, the clamping bracket 14 is not securely held by the respective
locking bracket 12. Thus, in Figure 2, the aircraft door 2 is able to be moved with
respect to the aircraft fuselage 4.
[0042] The locking bracket 12 shown in Figure 2 may be hooked onto the crossbar 30 of the
clamping bracket 14 shown in Figure 2, by rotating the shaft 8 about its longitudinal
axis in a direction indicated in Figure 2 by the solid arrow and the reference numeral
32. In other words, the locking bracket 12 shown in Figure 2 may be hooked onto the
crossbar 30 of the clamping bracket shown in Figure 2, by rotating the shaft 8 about
its longitudinal axis in an anti-clockwise direction. Doing so (i.e. rotating the
shaft 8 about its longitudinal axis in an anti-clockwise direction) would cause each
of the locking brackets 12 along the length of the shaft 8 to hook over a crossbar
30 of a respective clamping bracket 14.
[0043] Figure 3 is a schematic illustration (not to scale) of the components of the system
1 shown in Figure 2 after the shaft 8 has been rotated about its longitudinal axis,
in an anti-clockwise direction, such that the locking bracket 12 hooks onto the crossbar
30 of the respective clamping bracket 14.
[0044] The hooking of the locking brackets 12 onto their respective clamping brackets 14
causes the respective clamping bracket 14 to be held in fixed positions relative to
the locking brackets 12 (and therefore also the shaft 8 and shaft mounts 10). Thus,
by hooking the locking brackets 12 onto their respective clamping brackets 14, the
aircraft door 2 is securely held in a fixed position relative to the aircraft fuselage
4.
[0045] The locking bracket 12 shown in Figure 3 may be unhooked from the crossbar 30 of
the clamping bracket 14 shown in Figure 3, by rotating the shaft 8 about its longitudinal
axis in a direction indicated in Figure 3 by the solid arrow and the reference numeral
34, i.e. in a clockwise direction. Doing so (i.e. rotating the shaft 8 about its longitudinal
axis in a clockwise direction) would cause each of the locking brackets 12 along the
length of the shaft 8 to unhook from a crossbar 30 of a respective clamping bracket
14, thereby returning the system 1 to the configuration shown in Figure 2.
[0046] Figure 4 is a schematic illustration (not to scale) showing a perspective view of
the opposite side of the aircraft fuselage 4 to that which is shown in Figure 1. In
other words, Figure 4 shows further components of the system 1 (including the clamping
block 40) that are located at the side of the aircraft fuselage 4 at which the first
end 18 of the shaft 8 is located.
[0047] In this embodiment, the first end 18 of the shaft 8 comprises an outer bolt 36, a
notch 37, and an inner bolt 38. In this embodiment, the outer bolt 36, the notch 37,
and the inner bolt 38 are a single complete component that is located at an end of
the shaft 8.
[0048] The outer bolt 36 is a hexagonal bolt that is located at the free end of the first
end 18 of the shaft 8. The outer bolt 36 is located next to the notch 37. In this
embodiment, the maximum diameter of the outer bolt 36 is substantially the same as
the diameter of the portion of the shaft 8 that is coupled to the locking brackets
12 and shaft mounts 10.
[0049] The notch 37 is located at the first end 18 of the shaft 8, between the outer bolt
36 and the inner bolt 38. In this embodiment, the diameter of the notch is less than
the diameter of the outer bolt 36 and the inner bolt 38. In other words, the diameter
of the notch 37 is smaller than the diameter of the portion of the shaft 8 that is
coupled to the locking brackets 12 and shaft mounts 10.
[0050] The inner bolt 38 is a hexagonal bolt that is located along the shaft at an opposite
side of the notch 37 to the side of the notch 37 at which the outer bolt 36 is located.
In other words, the inner bolt 38 is located between the notch 37 and the portion
of the shaft 8 that is coupled to the locking brackets 12 and shaft mounts 10. In
this embodiment, the inner bolt 38 is substantially the same size and the outer bolt
36. In other words, the maximum diameter of the inner bolt 38 is substantially the
same as the diameter of the portion of the shaft 8 that is coupled to the locking
brackets 12 and shaft mounts 10.
[0051] In this embodiment, the clamping block 40 is made of metal. The clamping block 40
is fixed to the aircraft fuselage 4 by a fourth set of bolts, each of which is hereinafter
referred to as a "fourth bolt" and is indicated in the Figures by the reference numeral
42. Each of the fourth bolts 42 passes through the body of the clamping block 40 and
into the aircraft fuselage 4, thereby securely fixing the clamping block 40 the aircraft
fuselage 4. In this embodiment, the clamping block 40 is fixed to the aircraft fuselage
4 by four fourth bolts 42. However, in other embodiments, the clamping block 40 may
be fixed to the aircraft fuselage 4 by a different number of bolts, or using different
fixing means.
[0052] In this embodiment, the shape of the clamping block 40 is substantially that of a
plate with two wedge-shaped protrusions protruding from a surface of that plate. The
wedge shaped protrusions are hereinafter referred to as the "first wedge" (which is
indicated in Figure 4 by the reference numeral 44) and the "second wedge" (which is
indicated in Figure 4 by the reference numeral 46).
[0053] In this embodiment, the first wedge 44 comprises a plurality of holes (hereinafter
referred to as the "first wedge holes" and indicated in Figures by the reference numeral
48). The first wedge holes 48 extend from a top surface of the first wedge 44 into
the body of the first wedge 44. In this embodiment, there are six first wedge holes
44. However, in other embodiments there may be a different number of first wedge holes
48.
[0054] In this embodiment, the second wedge 46 comprises a plurality of holes (hereinafter
referred to as the "second wedge holes" and indicated in Figures by the reference
numeral 50). The second wedge holes 50 extend from a top surface of the second wedge
46 into the body of the second wedge 46. In this embodiment, there are seven second
wedge holes 50. However, in other embodiments there may be a different number of second
wedge holes 50.
[0055] In this embodiment, the surface of the aircraft fuselage 4 from which the first end
18 of the shaft 8 extends is substantially perpendicular to the longitudinal axis
of the shaft. Also, in this embodiment, the clamping block 40 is arranged such that
the top surfaces of the first wedge 44 and the second wedge 46 (i.e. the surfaces
of the wedges 44, 46 at which the wedge holes 48, 50 are located) are substantially
perpendicular to the longitudinal axis of the shaft 8. Also, in this embodiment, the
clamping block 40 is configured so that the top surfaces of the first wedge 44 and
the second wedge 46 are aligned with one another. Thus, in this embodiment, the shape
of the clamping block 40 advantageously allows that the clamping block 40 may be fixed
(using the fourth bolts 42) to a surface of the aircraft fuselage 4 that is not perpendicular
to the longitudinal axis of the shaft 8 whilst still providing surfaces (i.e. the
top surfaces of the wedges 44, 46) that are perpendicular to the longitudinal axis
of the shaft 8. In other embodiments, the clamping block 40 may have a different shape
such that the functionality of the clamping block 40 described herein is provided.
[0056] In this embodiment, the clamping block 40 is arranged such that the first wedge 44
is further away from the longitudinal axis of the shaft 8 than the second wedge 46.
In other words, the first wedge 44 is located at a greater distance from the shaft
8 (measured radially outwards from the shaft 8) than the second wedge 46.
[0057] In this embodiment, the clamping block 40 is arranged such that the first wedge holes
48 in the first wedge 44 lie along a circle whose centre lies along the longitudinal
axis of the shaft 8. Also, in this embodiment, the clamping block 40 is arranged such
that the second wedge holes 50 in the second wedge 50 each lie along one or two circles,
that have different diameters from each other, and whose centres each lie along the
longitudinal axis of the shaft 8.
[0058] A function of the clamping block 40 and the first end 18 of the shaft 8 will be described
in more detail later below with reference to Figure 6.
[0059] Figure 5 is a schematic illustration (not to scale) of a perspective view of a further
component of the system 1, namely the locking plate 52.
[0060] In this embodiment, the locking plate 52 is made of metal. In this embodiment, the
shape of the locking plate 52 is that of a cuboid having a rounded end portion (indicated
in Figure 5 by the reference numeral 53).
[0061] In this embodiment, the locking plate comprises a plurality of holes 54 - 60, each
of which passes through the body of the locking plate 52 from a front side of the
locking plate 52 to a rear side of the locking plate 52.
[0062] A first of the holes through the body of the locking plate 52 is hereinafter referred
to as the "shaft hole" and is indicated in Figure 5 by the reference numeral 54. The
shaft hole 54 is referred to as such because, as described in more detail later below
with reference to Figure 6, during use, the locking plate 52 is positioned such that
the shaft passes through the shaft hole 54.
[0063] In this embodiment, the shaft hole 54 is a "double hexagon hole", i.e. a hole the
shape of which is the same as the 12-pointed, 24-sided shape produced by positioning
two substantially identical hexagons such that their centre points are at the same
point and each point of one hexagon is radially aligned with a mid-point of a side
of the other hexagon.
[0064] In this embodiment, the shape of each of the hexagons that for the double hexagon
shaft hole 54 is substantially the same as the hexagonal cross section of the outer
and inner bolts 56, 58 of the first end 18 of the shaft 18.
[0065] The further holes through the body of the locking plate 52 are hereinafter referred
to as the "first bolt hole" (indicated in Figure 5 by the reference numeral 56), the
"second bolt hole" (indicated in Figure 5 by the reference numeral 58, and the "third
bolt hole" (indicated in Figure 5 by the reference numeral 60). The terminology "bolt
hole" is used to described the bolt holes 56, 58, 60 because, as described in more
detail later below with reference to Figure 6, during use, the locking plate 52 is
fixed to the clamping block 40 by passing bolts through a plurality of the bolt holes
56, 58, 60 and into wedge holes 48, 50 of the clamping block 40.
[0066] In this embodiment, the shape of each of the first bolt hole 56, the second bolt
hole 58, and the third bolt hole 60 is an oval.
[0067] In this embodiment, the distance (measured in a direction that is perpendicular to
the longitudinal axis of the shaft hole 54) between the longitudinal axis of the shaft
hole 54 and the first bolt hole 56 is substantially the same as the distance (measured
in a direction that is perpendicular to the longitudinal axis of the shaft 8) between
the longitudinal axis of the shaft 8 and the first wedge holes 48. Also, the distance
(measured in a direction that is perpendicular to the longitudinal axis of the shaft
hole 54) between the longitudinal axis of the shaft hole 54 and the second bolt hole
58 is substantially the same as the distance (measured in a direction that is perpendicular
to the longitudinal axis of the shaft 8) between the longitudinal axis of the shaft
8 and the second wedge holes 50 that lie along the larger of the two circles, centred
about the longitudinal axis of the shaft 8, along which second wedge holes 50 lie.
Also, the distance (measured in a direction that is perpendicular to the longitudinal
axis of the shaft hole 54) between the longitudinal axis of the shaft hole 54 and
the third bolt hole 60 is substantially the same as the distance (measured in a direction
that is perpendicular to the longitudinal axis of the shaft 8) between the longitudinal
axis of the shaft 8 and the second wedge holes 50 that lie along the smaller of the
two circles, centred about the longitudinal axis of the shaft 8, along which second
wedge holes 50 lie.
[0068] Thus, the fastening system 1 for securely fastening, or fixing, the aircraft door
2 against the aircraft fuselage 4 is provided.
[0069] Figure 6 is a process flow chart showing certain steps of an embodiment of a process
of using the above described fastening system 1 to fix the aircraft door 2 against
the aircraft fuselage 4.
[0070] It should be noted that certain of the process steps depicted in the flowchart of
Figure 6 and described below may be omitted or such process steps may be performed
in differing order to that presented below and shown in Figure 6. Furthermore, although
all the process steps have, for convenience and ease of understanding, been depicted
as discrete temporally-sequential steps, nevertheless some of the process steps may
in fact be performed simultaneously or at least overlapping to some extent temporally.
[0071] At step s2, the aircraft door 2 is closed, i.e. the aircraft door 2 is moved against
the aircraft fuselage 4. This may be performed manually or automatically. In this
embodiment, the closing of the aircraft door 2 against the aircraft fuselage 4 causes
each of the clamping brackets 14 to be positioned opposite to a respective locking
bracket 12. In other words, the closing of the aircraft door 2 moves the clamping
brackets to be in a position whereby, by rotating the shaft 8, the clamping brackets
14 may be engaged (i.e. hooked onto) by the locking brackets 12.
[0072] In this embodiment, after closing the aircraft door 2, the arrangement of the locking
brackets 12 and clamping brackets 14 is that same as that shown in Figure 2 and described
above.
[0073] At step s4, the shaft 8 is rotated, about its longitudinal axis, in an anti-clockwise
direction. Rotation of the shaft may be performed by any appropriate means, for example
automatically (e.g. using a motor or actuator) or manually.
[0074] In this embodiment, the rotation of the shaft 8, in an anti-clockwise direction,
about its longitudinal axis causes each of the locking brackets 12 to hook onto a
crossbar 30 of a respective clamping bracket 14. Such rotation of the shaft 8 may
cause the aircraft door 2 to be pulled closer to the aircraft fuselage 4. The engagement
of the clamping brackets 14 by the locking brackets 12 (i.e. the hooking of the locking
brackets 12 onto the crossbars 30 of the clamping brackets 14) may fix the position
of the aircraft door 2 with respect to aircraft fuselage 14. In other words, the engagement
of the clamping brackets 14 by the locking brackets 12 may fasten the aircraft door
2 closed (against the aircraft fuselage 4).
[0075] In this embodiment, after rotating the shaft 8, in an anti-clockwise direction, about
its longitudinal axis, the arrangement of the locking brackets 12 and clamping brackets
14 is that same as that shown in Figure 3 and described above.
[0076] At step s6 the locking plate 52 is positioned over the first end 18 of the shaft
8 such that the shaft hole 54 is around the notch 37. In other words, the shaft hole
54 of the locking plate 52 is passed over the outer bolt 36 such that the shaft hole
54 is around the notch 37. In this embodiment, because the diameter of the notch 37
is less than the diameter of the outer and inner bolts 36, 38 (and therefore less
than the diameter of the shaft hole 54), the locking plate 52 may be freely rotated
about the shaft 8 (i.e. about the longitudinal axis of the shaft 8).
[0077] In this embodiment, the positioning of the locking plate 52 around the notch 37 is
performed by a human operator.
[0078] At step s8, the human operator couples a spanner to the outer bolt 36 of the first
end of the shaft 8. In particular, the spanner is coupled to the outer bolt 36 such
that the jaws of the spanner grip the outer bolt 36, and a clamping bracket of the
spanner extends radially outwards from the shaft 8.
[0079] At step s10, using the spanner, the human operator may further rotate the shaft 8,
in an anti-clockwise direction, about the longitudinal axis of the shaft 8. This may
cause the aircraft door 2 to be pulled further towards the aircraft fuselage 4. Thus,
the aircraft door 2 may be tightly sealed against the fuselage 4.
[0080] At step s12, whilst the rotational force applied to the shaft 8 by the human operator
using the spanner is maintained, the locking plate 52 is slid along the length of
the shaft 8 (in a direction that points from the first end 18 of the shaft 8 to the
second end 20 of the shaft) such that the shaft hole 54 is moved from being around
the notch 37 to being around the inner bolt 38. Since a hexagon shape of the shaft
hole 54 is substantially the same size and the inner bolt 36, movement of the locking
plate 52, other than in a direction parallel to the longitudinal axis of the shaft
8, is opposed. In particular, when the shaft hole 54 is positioned around the inner
bolt 36, the locking plate 52 is not free to rotate around the shaft 8. The locking
plate 52 may grip the shaft 8 in a "spanner-like" fashion.
[0081] In this embodiment, prior to being slid along the shaft 8, the locking plate 52 is
rotated such that, when the locking plate 52 is slid along the length of the shaft
8, the locking plate 52 contacts with the first and second wedges 44, 46 of the clamping
block 40.
[0082] As described in more detail earlier above with reference to Figure 4, the top surfaces
of the first wedge 44 and the second wedge 46 (i.e. the surfaces of the wedges 44,
46 at which the wedge holes 48, 50 are located) are substantially perpendicular to
the longitudinal axis of the shaft 8, and top surfaces of the first wedge 44 and the
second wedge 46 are aligned with one another. Thus, when the locking plate 52 is slid
along the length of the shaft 8 (such that the shaft hole 54 is around the inner bolt
38), the locking plate 52 contacts with the both first and second wedges 44, 46 of
the clamping block 40 .
[0083] At step s14, using the spanner, the human operator rotates the shaft 8, by a relatively
small amount, in either a clockwise or an anti-clockwise direction, about the longitudinal
axis of the shaft 8. Since the shaft hole 54 is around the inner bolt 38, and a hexagon
shape of the shaft hole 54 is substantially the same size and the inner bolt 36, the
rotation of the shaft 8 about its longitudinal axis causes the locking plate 52 to
rotate about the longitudinal axis of the shaft 8. In this embodiment, the shaft is
rotated until the first bolt hole 56 is aligned with one of the first wedge holes
48 and either the second bolt hole 58 is aligned with one of the second wedge holes
50 or the third bolt hole 60 is aligned with one of the second wedge holes 50. In
this embodiment, the shaft 8 is rotated by the minimum distance required for the first
bolt hole 56 to be aligned with one of the first wedge holes 48 and either the second
bolt hole 58 to be aligned with one of the second wedge holes 50 or the third bolt
hole 60 to be aligned with one of the second wedge holes 50.
[0084] Figure 7 is a schematic illustration (not to scale) showing an example configuration
of the inner bolt 36, the locking plate 52, and the clamping block 40 at step s14.
Figure 7 shows an example position of the inner bolt 36, the locking plate 52, and
the clamping block 40 when viewed along the longitudinal axis of the shaft 8, in a
direction that points from the first end 18 of the shaft 8 to the second end 20 of
the shaft 20.
[0085] In this example, the shaft hole 54 of the locking plate 52 is around the inner bolt
36. Also, in this example, the locking plate 52 has been positioned such that it is
in contact with the first wedge 44 and the second wedge 46. Also, in this example,
the locking plate 52 has been positioned such that the first bolt hole 56 is aligned
with a first wedge hole 48. Also, in this example, the locking plate 52 has been positioned
such that the second bolt hole 58 is aligned with a second wedge hole 50. In other
examples, the locking plate 52 may be positioned such that the third bolt hole 58
is aligned with a second wedge hole 50 instead of or in addition to the second bolt
hole 58 being aligned with a second wedge hole 50.
[0086] At step s16, the locking plate 52 is bolted to the clamping block 40. In this embodiment,
this bolting of the locking plate 52 to the clamping block 40 is performed by passing
bolts, hereinafter referred to as the "fifth bolts", through each of the bolt holes
56, 58, 60 that have been aligned with a wedge hole 48, 50, and into the wedge hole
48, 58 with which that bolt hole 56, 58, 60 has been aligned.
[0087] Figure 8 is a schematic illustration (not to scale) showing a perspective view of
the fastening system components shown in Figure 7, after the locking plate 52 has
been bolted to the clamping block 40.
[0088] In this example, the shaft hole 54 of the locking plate 52 is around the inner bolt
36 and the locking plate 52 is in contact with the first wedge 44 and the second wedge
46. Also, in this example, the locking plate 52 has been bolted to the clamping block
40 by a fifth bolt 62 that passes through the first bolt hole 56 and into a first
wedge hole 48 of the clamping block 40. Also, in this example, the locking plate 52
has been bolted to the clamping block 40 by a further fifth bolt 62 that passes through
the second bolt hole 58 and into a second wedge hole 50 of the clamping block 40.
[0089] The locking plate 52, in effect, is a lever about a fulcrum (which in this case is
the longitudinal axis of the shaft 8). This advantageously provides that, if the shaft
8 tries to rotate about its longitudinal axis, the force that would be experienced
by the fifth bolts 62 (and the clamping block 40) tends to be significantly lower
than the force rotating the shaft 8. Thus, the fifth bolts 62 and clamping block 40
tend to be able to prevent rotation of the shaft 8 even when larger rotations forces
are applied to the shaft 8.
[0090] The use of two separate fifth bolts 62 to bolt the locking plate 52 to the clamping
block 40 advantageously provides a level of redundancy. Thus, for example, is one
of the fifth bolts 62 were to break, or come loose, the other fifth bolt 62 would
still fix the locking plate 52 to the clamping block 40. In other embodiments, a different
number of bolts may be used to fix the locking plate 52 to the clamping block 40,
or different fixing means may be used.
[0091] In this embodiment, the bolting of the locking plate 52 to the clamping block 40
is such that the position of the locking plate 52 is substantially fixed relative
to the clamping block 40. In other words, the bolting of the locking plate 52 to the
clamping block 40 is such that the position of the locking plate 52 is the locking
plate 52 is substantially immovable relative to the clamping block 40. Since the clamping
block 40 is fixed relative to the aircraft fuselage 4, the position of the locking
plate 52 relative to the aircraft fuselage is substantially fixed.
[0092] Thus, since the position of the shaft 8 may not rotate about its longitudinal axis
without rotating, about the longitudinal axis of the shaft, the locking plate 52 (because
the shaft hole 54 is around the inner bolt 36), the bolting of the locking plate 52
to the clamping block 40 tends to prevent rotation of the shaft 8 about its longitudinal
axis.
[0093] Thus, the positions of the locking brackets 12 on the shaft tend to be maintained.
[0094] Thus, since the locking brackets 12 are engaged with, i.e. hooked onto, the clamping
brackets 14 (which are fixed relative to the aircraft door 2), the position of the
aircraft door 2 relative to aircraft fuselage 4 is substantially fixed.
[0095] Thus, the aircraft door 2 is held tightly closed against the aircraft fuselage 4,
and movement of the aircraft door 2 (e.g. unwanted opening of the aircraft door) tends
to be prevented.
[0096] The bolting of the locking plate 52 to the clamping block 40 in effect "locks" the
aircraft door 2 in a closed position against the aircraft fuselage 4.
[0097] Thus, a process of using the above described fastening system 1 to fix the aircraft
door 2 against the aircraft fuselage 4 is provided. The aircraft door 2 may be released
(i.e. such that it is moveable with respect to the aircraft fuselage 4) by reversing
to the method steps of Figure 6.
[0098] An advantage provided by the above described system and method is that an aircraft
hangar door may be closed (by simply rotating the shaft) and fixed in position (by
bolting the locking plate to the clamping block so that the shaft cannot further rotate)
faster and more simply than using conventional methods. The aircraft hangar door may
be fixed in position using only two bolts (namely the fifth bolt which bolt the locking
plate to the clamping block). This is in contrast to conventional systems and methods
which typically use, for example, 40-60 bolts to secure an aircraft hangar door.
[0099] The fastening system may located within the aircraft whose door is fastened by the
fastening system. Thus, when the door is closed and fixed in position, an external
surface of the aircraft door may be flush with a external surface of the rest of the
aircraft fuselage. This may be because no external bolt fastenings are use to close
and fix in position the aircraft door. This tends to improve the aerodynamic properties
of the aircraft. Also, this tends to reduce the likelihood of the aircraft being detected
by radar.
[0100] Enabling the aircraft doors to be closed and fixed relatively quickly and simply
tends to allow for the doors of the aircraft to be secured, whilst the aircraft is
on the ground, without the aircraft overheating. This is particularly useful in warm
climates.
[0101] A relatively simple, easy to use locking mechanism for preventing avionics bay doors
of an aircraft from opening during flight is provided.
[0102] The above described fastening system advantageously tends to be accessible on the
aircraft, e.g. by a human operator, even when the aircraft engine is running.
[0103] The first end of the shaft and clamping block may be located within a main undercarriage
bay of the aircraft. Thus, the first end of the shaft tends to be easy to access by
a human operator. Also, the first end of the shaft and clamping block tend to be hidden
when the aircraft undercarriage is retracted, thereby reducing the likelihood that
first end of the shaft and clamping block are impacted by Foreign Object Debris, or
are tampered with.
[0104] Advantageously, the above describe door fastening system may be relatively easily
retrofitted to existing aircraft.
[0105] The components of the above described fastening systems are made of metal, e.g. steel,
which tends to be advantageously strong.
[0106] Advantageously, the above describe door fastening system tends to be useable on any
aircraft platform.
[0107] An advantage provided by the above described system is that the clamping block and
the locking plates are configured such that (when the locking plate is arranged such
that the shaft hole is around the inner bolt of the shaft) at least two of the bolt
holes in the locking plate may each be aligned with a respective wedge hole in the
clamping block. This allows the locking plate to be bolted to the clamping block using
at least two fifth bolts, thereby providing a level of redundancy. Furthermore, if
the fifth bolts become loose, the shafts of the fifth bolts would tend to still hold
the shaft clamped in position.
[0108] An advantage provided by the "double hexagon" shape of the shaft hole is that are
greater number of options for positioning the locking plate such that it grips the
inner bolt are provided (compared to if the shaft hole was a single hexagon shaped
hole). This tends to facilitate the positioning of the locking plate such that the
inner bolt is gripped by the locking plate, and such that the bolt holes of the locking
plates are aligned with the wedge holes of the clamping block.
[0109] The so-called "double nut" first end of the shaft (i.e. the inner and out nuts with
the notch in between those nuts) allows an operator, using a spanner, to manually
adjust a position of the shaft. Thus, a human operator may, for example, rotate the
shaft anti-clockwise so that the aircraft door is pulled further towards the aircraft
fuselage. Also, a human operator may, for example when the locking plate is positioned
around the inner bolt, rotate the shaft to align the bolt holes of the locking plate
with the wedge holes of the clamping block. The notch advantageously provides that
the locking plate may be free rotated around the shaft before being slid over the
inner bolt. This facilitates alignment of the bolt holes of the locking plate with
the wedge holes of the clamping block.
[0110] A further advantage provided by the above described apparatus and method is that
if, for some reason, the clamping block and/or locking plate were to fail, the aircraft
door would still tend to be held in a closed position by the locking brackets and
clamping brackets.
[0111] In the above embodiments, the fastening system is used to fasten an aircraft door
or hinged access panel closed. In other words, the fastening system is used to fix
an aircraft door or hinged access panel, in a closed position, so that it does not
move with respect to the rest of the aircraft fuselage. However, in other embodiments,
the fastening system may be used to fix different types of entities (i.e. other than
aircraft hinged access panels and/or fuselages) to one another. For example, in other
embodiments, the fastening system may be used to fix a different type of aircraft
door relative to the fuselage.
[0112] In the above embodiments the locking plate and the clamping block are used to prevent
or oppose the rotation of a bolt that is connected to a shaft. However in other embodiments,
the locking plate and the clamping block are used to prevent or oppose the rotation
of a different entity. For example, in other embodiments, the locking plate and the
clamping block may be used to prevent or oppose the rotation of a bolt that is connected
to a further shaft that serves a different purpose to the shaft described in the above
embodiments.
[0113] In other embodiments, any or all of the components of the fastening systems may be
shaped differently, and/or made from a different appropriate material, to that described
above such that the above described functionality is provided.
[0114] In other embodiments, micro switches or other electronic devices may be used to indicate
to an operator (e.g. a pilot of the aircraft) that all clamps are fully engaged and
the aircraft door is being held in the closed position.
1. Locking apparatus for securing an aircraft door or access panel (2) in an opening
formed in an aircraft fuselage (4), the locking apparatus comprising:
a shaft (8) having a longitudinal axis;
at least one mounting member (10) for mounting the shaft (8) to the aircraft fuselage
(4) such that the shaft (8) may be rotated about its longitudinal axis;
securing means (12) fixedly mounted to the shaft (8) and arranged such that:
rotation of the shaft (8) about its longitudinal axis moves the securing means (12)
from being in a first position to being in a second position;
the first position of the securing means (12) is a position in which the securing
means (12) are not coupled to the aircraft door or panel (2), thereby allowing movement
of the aircraft door or panel (2) relative to the aircraft fuselage (4); and
the second position of the securing means (12) is a position in which the securing
means (12) are coupled to the aircraft door or panel (2), thereby preventing movement
of the aircraft door or panel (2) relative to the aircraft fuselage (4);
a locking member (52) for coupling to the shaft (8) such that rotation of the shaft
(8) about its longitudinal axis causes movement of the locking member (52); and
fixing means for, when the shaft (8) has been rotated such that the securing means
(12) are in the second position, fixedly attaching the locking member (52) to the
aircraft fuselage (4) thereby preventing rotation of the shaft (8).
2. Locking apparatus according to claim 1, wherein the locking member (52) is configured
to be coupled to the shaft (8) such that the locking member (52) forms a lever that
is rotatable about a fulcrum, the fulcrum being the longitudinal axis of the shaft
(8).
3. Locking apparatus according to claim 2, wherein the locking member (52) is configured
to be fixedly attached, by the fixing means, to the aircraft fuselage (4) at a point
along a length of the locking member (52) that is proximate to a distal end of the
locking member (52).
4. Locking apparatus according to any of claims 1 to 3, wherein the locking member (52)
is configured to be fixedly attached, by the fixing means, to the aircraft fuselage
(4), at a plurality of different points on the locking member (52).
5. Locking apparatus according to any of claims 1 to 4, wherein:
the shaft (8) comprises a bolt (38), a longitudinal axis of the bolt (38) being aligned
with the longitudinal axis of the shaft (8); and
the locking member (52) comprises a hole (54), the shape of the hole (54) corresponding
to the shape of the bolt (38) such that the locking member (52) may be coupled to
the shaft (8) by positioning the locking member (52) relative to the shaft (8) such
that the bolt (38) is in the hole (54).
6. Locking apparatus according to claim 5, wherein the shaft (8) comprises a notch (37),
a diameter of the notch (37) being less than a diameter of the hole (54) in the locking
member (52) such that, when the locking member (52) is positioned relative to the
shaft (8) such that the notch (37) is in the hole (54), the locking member (52) may
be rotated about the longitudinal axis of the shaft (8) without the shaft (8) being
rotated, thereby allowing an orientation of the locking member (52) relative to the
shaft (8) to the adjusted.
7. Locking apparatus according to any of claims 1 to 6, wherein the shaft (8) comprises
an adjustment bolt (36), a longitudinal axis of the adjustment bolt (36) being aligned
with the longitudinal axis of the shaft (8), the adjustment bolt (36) being positioned
at point along the length of the shaft (8) such that, using the adjustment bolt (36),
a human operator may rotate the shaft (8).
8. Locking apparatus according to any of claims 1 to 7, wherein
the fixing means comprises a clamping block (40) that is fixedly attached to the aircraft
fuselage (4) and is configured to provide one or more surfaces (44, 46) that are substantially
perpendicular to the longitudinal axis of the shaft (8); and
the locking member (52) is fixedly attached to the aircraft fuselage (4) by fixedly
attaching the locking member (52) to a surface (44, 46) of the clamping block (40)
that is substantially perpendicular to the longitudinal axis of the shaft (8).
9. Locking apparatus according to claim 8, wherein the locking member (52) is configured
to be fixedly attached the clamping block (40) by, for one of more bolts (62), positioning
each of those bolts (62) such that that bolt (62) is within a respective hole (56,
58, 60) through the locking member (52) and in a respective hole (48, 50) in the clamping
block (40).
10. Locking apparatus according to any of claims 1 to 9, the locking apparatus further
comprising one or more clamping brackets (14) fixedly attached to the aircraft door
or panel (2), wherein the securing means (12) are configured to attach to the one
or more clamping brackets (14).
11. Locking apparatus according to claim 10, the securing means (12) includes one or more
locking brackets (12), each locking bracket (12) being fixedly attached to the shaft
(8) at a position along the length of the shaft (8), each locking bracket (12) being
configured to be hooked onto a respective clamping bracket (14) such that that clamping
bracket (14) is securely held by that locking bracket (12).
12. Locking apparatus according to any of claims 1 to 11, wherein the aircraft door or
panel (2) is a hinged door or panel.
13. Locking apparatus according to any of claims 1 to 12, wherein the shaft (8), the at
least one mounting member (10), the securing means (12), the locking member (52),
and the fixing means are made of metal.
14. An aircraft comprising:
an aircraft door or access panel (2);
an aircraft fuselage (4); and
locking apparatus for securing the aircraft door or access panel (2) in an opening
formed in the aircraft fuselage (4), the locking apparatus being in accordance with
any of claims 1 to 13.
15. A method of securing an aircraft door or access panel (2) in an opening formed in
an aircraft fuselage (4), the method comprising:
providing a shaft (8) having a longitudinal axis, the shaft (8) being mounted, by
at least one mounting member (10), to the aircraft fuselage (4) such that the shaft
(8) may be rotated about its longitudinal axis;
providing securing means (12), the securing means (12) being fixedly mounted to the
shaft (8);
rotating the shaft (8), thereby moving the securing means (12) from being in a first
position to being in a second position; wherein
the first position of the securing means (12) is a position in which the securing
means (12) are not coupled to the aircraft door or panel (2), thereby allowing movement
of the aircraft door or panel (2) relative to the aircraft fuselage (4); and
the second position of the securing means (12) is a position in which the securing
means (12) are coupled to the aircraft door or panel (2), thereby opposing movement
of the aircraft door or panel (2) relative to the aircraft fuselage (4);
coupling a locking member (52) to the shaft (8) such that rotation of the shaft (8)
about its longitudinal axis causes movement of the locking member (52); and
when the shaft (8) has been rotated such that the securing means (12) are in the second
position, fixedly attaching, using fixing means, to the aircraft fuselage (4), the
locking member (52), thereby preventing the shaft (8) from rotating.